Mình đang cần gấp mình sẽ cho 5 sao

Tính bằng cách thuận tiện nhất: 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56

Nhờ các bạn cách nào hợp lý nhất

E= 5x^2 -7xy -24y^2. Mn giải giúp e vs ạ ghi cách giải cụ thể nha

Mọi người giúp em câu này với ạ: a) Tính pH của dung dịch đệm chứa CH3COOH 0,1M và CH3COONa 0,1M và biết pKa (CH3COOH) = 4,75. b). Nếu thêm 10^-2 mol HCl vào 1l dung dịch đệm trên thì pH sẽ thay đổi như thế nào? so sánh với trường hợp thêm 10^-2 mol HCl vào 1l nước cất?

Tìm 2 số chẵn liên tiếp biết rằng tích 2 số đầu ít hơn tích 2 số sau là 32

Có bao nhiêu hình tứ giác? trả lời giùm em với ạ

VII. Fill in each blank with a suitable word (2 points) Nowadays people are more aware that wildlife all over the world is in (1) ..................... Many species of animals are threatened, and could easily become extinct if we do not (2)........................an effort to protect them. There are many reasons for this. In some cases, animals are hunted for their fur or for other (3)..................... parts of their bodies. Some birds, such as parrots, are caught alive, and sold (4).............pets. For many animals and birds, the problem is that their (5)........................- the place where they live is disappearing. More land is (6)...................for farms, houses or industry, and there are fewer open spaces (7)..........there once were. Farmers use powerful chemicals to help them grow better crops, (8)..................these chemicals pollute the environment and harm wildlife. The most successful animals on earth- human (9)......................- will soon be the only ones left, unless we can (10)....................this problem. c. another 7. a. handle D. different types of lists. SECTION D: WRITING: X. Sentence transformation (2 points) Rewrite the following sentences in such a way that the second sentence has the same meaning as the first one 1.It's my opinion that you should take more exersise. If I were............................................................................................................................. 2.He never suspected that the money had been stolen. At no time ........................................................................................................................ 3. You have ridden a horse before, haven't you? Have................................................................................................... 4. I'm quite happy to look after the baby for you. I don't................................................................................................................................ 5. Vietnamese women continue to wear the fashionable Ao dai. The fashionable Ao dai............................................................................. 6. "Would you like to go to the concert with me tonight?" Peter said to Ann. Peter invited................................................................................................ 7. He was annoyed because his son often came home late. He objected.................................................................................................................... 8. She dances beautifully and she sings sweetly, too. Not only ....................................................................................................................... 9. Thomas and David are very good friends. Thomas and David get..................................................................................................... 10. Driving on the left is strange and difficult for Americans. Americans aren't.............................................................................................................. XI. Sentence building (2 points) Use the following sets of words and phrases to write a letter. Make all the changes and additions if necessary. Dear Na, I/ already/ arrive home/ New York ...................................................................................................... 2. It/ happy/ see/ whole family again. ...................................................................................................... 3. Thank/ for/ lovely time/ you/ house ...................................................................................................... 4. It/ kind/ you/ show me so much/ hometown ...................................................................................................... 5. I/ really impressed/ friendliness/ your people ...................................................................................................... 6. mountainous sights/ make/ deep impression/ me ...................................................................................................... 7. I still remember/ invited/ eat/ sour meat/ and/ it/ delicious ...................................................................................................... 8. your homeland/ beautiful/ so/ I wish/ have a chance/ visit/ again ...................................................................................................... 9. If/ you/ time/ write/ me ...................................................................................................... 10. I/ look/ hear/ you/. Give/ regards/ parents ...................................................................................................... Love, Daisy

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